US9133393B2 - Oxynitride-based phosphor - Google Patents

Oxynitride-based phosphor Download PDF

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US9133393B2
US9133393B2 US13/876,847 US201213876847A US9133393B2 US 9133393 B2 US9133393 B2 US 9133393B2 US 201213876847 A US201213876847 A US 201213876847A US 9133393 B2 US9133393 B2 US 9133393B2
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phosphor
oxynitride
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light
composition
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Kee Sun Sohn
Un Bae PARK
Nam Soo Shin
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Sunchon National University SCNU
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    • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
    • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
    • C09K11/77—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals
    • C09K11/7783—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals one of which being europium
    • C09K11/7784—Chalcogenides
    • C09K11/7786—Chalcogenides with alkaline earth metals
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
    • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
    • H10H20/80—Constructional details
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
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    • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
    • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
    • C09K11/0883—Arsenides; Nitrides; Phosphides
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
    • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
    • C09K11/77—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals
    • C09K11/7701—Chalogenides
    • C09K11/7703—Chalogenides with alkaline earth metals
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
    • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
    • C09K11/77—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals
    • C09K11/7766—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals
    • C09K11/7767—Chalcogenides
    • C09K11/7768—Chalcogenides with alkaline earth metals
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
    • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
    • C09K11/77—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals
    • C09K11/7783—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals one of which being europium
    • C09K11/7784—Chalcogenides
    • C09K11/7787—Oxides
    • H01L33/502—
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
    • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
    • H10H20/80—Constructional details
    • H10H20/85—Packages
    • H10H20/851—Wavelength conversion means
    • H10H20/8511—Wavelength conversion means characterised by their material, e.g. binder
    • H10H20/8512—Wavelength conversion materials

Definitions

  • the present invention relates to a phosphor having a novel crystalline structure, and more particularly, to a novel oxynitride-based phosphor including oxynitride having a good durability, possibly emitting diverse colors from green to yellow when using a blue emitting diode or a ultraviolet emitting diode as an excitation source, and appropriately applicable for replacing or complementing a SIALON phosphor, in particular.
  • a white LED light emitting apparatus recently getting the limelight as a lighting, an LCD backlight, an automobile light, and the like, commonly includes an LED light emitting device emitting blue or near ultraviolet light and a phosphor transforming wavelengths into visible light by using the emitted light from the light emitting device as an excitation source.
  • a blue light emitting diode using InGaN-based material having a wavelength of 450 to 550 nm is used as a light emitting device, and a yellow light emitting YAG-based phosphor represented by the empirical formula of (Y,Gd) 3 (Al,Ga) 5 O 12 is used as a phosphor.
  • the blue light emitted from the light emitting device is incident to a phosphor layer, and absorption and reflection of the light are repeated for several times by the phosphor layer.
  • the absorbed blue light by the phosphor may be transformed into yellow light.
  • the transformed yellow light and a portion of the incident blue light are mixed and appreciated as white light through the eyes of a viewer.
  • the white LED having the above-described structure includes a small amount of red component in the light, has a high color temperature, and lacks of red and green components. Thus, only lightings having deteriorated color rendering properties may be obtained.
  • an oxide-based phosphor generally tends to decrease light intensity when the wavelength of the excitation source exceeds 400 nm. In this case, a highly luminescent white light may not be obtained by using the blue light.
  • an oxynitride-based phosphor having stability better or equal to that of the oxide phosphor and having a good light emitting efficiency at an excitation source exceeding 400 nm attracts much concern in the white LED field, recently.
  • the oxynitride-based phosphor since the oxynitride-based phosphor has been originally developed as engineering ceramics, the efficiency decrease and color change due to humidity and heat are small.
  • the purpose of the present invention is to provide a phosphor made by using oxynitride, having a good structural stability, having a good light emitting luminance particularly at yellow color, deviated from the component region of a common sialon phosphor, having a novel crystalline structure for easily improving the light emitting luminance, and being appropriately used in an LED field.
  • a novel phosphor composition made by using oxynitride having structural stability, good durability and good luminance properties, and so, applicable as a phosphor for a lighting such as a white LED
  • an oxynitride including Ca, La and Si and having a certain composition is found to form a monoclinic inorganic crystalline structure, and a phosphor having the inorganic crystalline structure as a host material may emit light from green to yellow with a high luminance.
  • the crystalline structure of the oxynitride-based phosphor according to the present invention differs from well known other nitridosilicate such as SrSi 2 N 2 O 2 and ⁇ -/ ⁇ -SIALON phosphors.
  • an oxynitride-based phosphor including a host material represented by the general formula of (Ca 1-x M1 x ) a (La 1-y M2 y ) b Si c N d O e (in which 0.5 ⁇ b/a ⁇ 7, 1.5 ⁇ c/(a+b) ⁇ 3.5, 1 ⁇ d/c ⁇ 1.8, 0.6 ⁇ e/(a+b) ⁇ 2, 0 ⁇ x ⁇ 0.5, and 0 ⁇ y ⁇ 0.5) and having a monoclinic crystalline structure, and at least one dissolved activator selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Tb, Ho, Er, Tm and Yb is provided.
  • the M1 is at least one element selected from Ba, Mg, Sr, Mn and Zn
  • the M2 is at least one element selected from Y, Lu, Sc, Gd, Tb, Ce, Nd, Sm, Dy, Ho, Er, Tm, Yb, Al, Ga, Ge, Sn and In.
  • the relation of a, b and c may be defined by a triple element composition designating diagram in FIG. 4 .
  • the host material may include a phase illustrating diffraction peaks in ranges of Bragg angles (28) of 10.68° to 11.41°, 18.52° to 19.46°, 31.58° to 31.21° and 36.81° to 37.49°, as a representative phase, and the peaks of the representative phase have relative intensity of greater than or equal to 5% when the relative intensity of the most intensive diffraction peak in a powder X-ray diffraction pattern by Co K ⁇ line is 100%.
  • the crystalline structure of the representative phase may be monoclinic.
  • the oxynitride-based phosphor according to the present invention may have the following composition represented by the following [Equation 1]. (Ca 1-x M1 x ) a-z (La 1-y M2 y ) b Si c N d O e :M3 z [Equation 1]
  • the M1 is at least one element selected from Ba, Mg, Sr, Mn and Zn
  • the M2 is at least one element selected from Y, Lu, Sc, Gd, Tb, Ce, Nd, Sm, Dy, Ho, Er, Tm, Yb, Al, Ga, Ge, Sn and In
  • the M3 is at least one element selected from Mn, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Tb, Ho, Er, Tm and Yb.
  • the a may be 1 to 30, the b may be 0.8a to 2a, and the c may be 1.8(a+b) to 3.2(a+b).
  • the M3 may include Eu.
  • the x may be 0 to 0.1 and the y may be 0 to 0.1.
  • the z may be 0.001 to 0.1, and more preferably, 0.03 to 0.07.
  • the phosphor according to the present invention may emit light of 500 to 600 nm wavelength by the radiation of an excitation source having 360 to 500 nm wavelength.
  • a phosphor composition based on Ca, La, Si, 0 and N and having a monoclinic crystalline structure as in the present invention has not been reported until now.
  • the composition may be used as blue, greenish yellow and yellow phosphors when doped with Eu, Ce, Mn and the like.
  • the light efficiency of the phosphor is good particularly when doped with Eu, and the Eu doped phosphor may be appropriately used as the phosphor for the LED.
  • the phosphor of the present invention is formed by using oxynitride and has good structural stability, the stability in an environment including an oxidation atmosphere or humidity is good.
  • a radiationless deactivation by which excited electrons emit heat to come back to a ground state is restrained.
  • the light emitting efficiency may be increased and good luminance properties may be obtained.
  • the wavelength of the light may be changed from green to yellow by replacing Ca, La site with a material having the same oxidation number by controlling the molar ratio of the constituting elements in the phosphor of the present invention.
  • the light emitting efficiency may be changed, and the wavelength of the emitted light may be changed according to the Eu doping concentration.
  • the phosphor of the present invention may be used as a phosphor for tuning.
  • FIG. 1A is a diagram illustrating a precise XRD analysis result of a phosphor manufactured according to Example 4 of the present invention by using an accelerator light source
  • FIG. 1B is a diagram illustrating an analysis result of a phosphor manufactured according to Example 4 of the present invention by using a common XRD analysis apparatus.
  • FIG. 2 is a diagram illustrating an XRD analysis result on the phosphors manufactured according to Examples 8 to 14 of the present invention when Ca or La is replaced with Mg, Sr, Ba, Y, Sc, Gd or Tb in a host material by about 10%, with respect to that according to Example 4.
  • FIG. 3 is a diagram illustrating a TEM analysis result on the phosphor manufactured according to Example 4 of the present invention.
  • FIG. 4 is a diagram illustrating component ranges for forming a phosphor having a single phase monoclinic crystalline structure according to the present invention.
  • FIG. 5 is a diagram illustrating the light emitting properties of phosphors including different Eu 2 ⁇ doping amounts according to Examples 1 to 7 of the present invention.
  • FIG. 6 is a diagram illustrating a normalized result on the intensity in FIG. 5 .
  • FIG. 7 is a diagram illustrating light emitting properties of the phosphors manufactured according to Examples 8 to 14 according to the present invention.
  • FIG. 8 is a diagram illustrating the light emitting properties of phosphors manufactured according to Examples 15 and 16 of the present invention.
  • the M1 is at least one element selected from Ba, Mg, Sr, Mn and Zn
  • the M2 is at least one element selected from Y, Lu, Sc, Gd, Tb, Ce, Nd, Sm, Dy, Ho, Er, Tm, Yb, Al, Ga, Ge, Sn and In.
  • the relation between a, b and c may be more particularly defined by a triple element composition designating diagram in FIG. 4 .
  • the phosphor according to the present invention is an oxynitride-based phosphor mainly including Ca, La, Si, N and 0. Even though a portion of the Ca is replaced with Ba, Mg, Sr, Mn and Zn, and a portion of the La is replaced with Y, Lu, Sc, Gd, Tb and Ce, the phosphor has a monoclinic crystalline structure in which the lengths of three crystalline axes of a, b and c are different from each other, the a-axis is perpendicular to the b-axis and the c-axis, however, the b-axis and the c-axis are not perpendicular to each other.
  • the Eu and the like is dissolved as a central metal element for emitting light, and when the phosphor is exposed to an excitation source of ultraviolet or visible light, the phosphor composition emits green, yellowish green or yellow light.
  • the “a” is a numerical of a proportional constant and may be any value, however, may be preferably in a range of 1 to 30 when represented by a chemical formula obtained through a subsequent accurate structure analysis.
  • the “a” is more preferably, in a range of 1 to 10 when considering the chemical formula of a common crystalline structure.
  • the preferred range of “b” is 0.5a to 7a.
  • the “b” is less than 0.5a or exceeds 7a, the crystalline structure may change to other than the monoclinic structure, and the properties of the phosphor according to the present invention may be unobtainable.
  • the “b” is more preferably in the range of 0.8a to 2a.
  • the preferred range of the “c” is 1.5(a+b) ⁇ c ⁇ 3.5(a+b).
  • the “c” is less than 1.5(a+b) or exceeds 3.5(a+b)
  • the crystalline structure may change to other than the monoclinic structure, and the properties of the phosphor according to the present invention may be unobtainable.
  • the “c” is more preferably, in the range of 1.8(a+b) to 3.2(a+b).
  • the composition of nitrogen may be roughly controlled by the “c” value, however, an accurate control may be impossible.
  • the “d” is preferably in the range of 1c ⁇ d ⁇ 1.8c.
  • the composition of oxygen may be roughly controlled by the “a” value and the “b” value, however, an accurate control may be impossible.
  • the range of 0.6(a+b) e 2(a+b) is preferable.
  • the phosphor of the present invention up to 50% of Ca may be replaced with Ba, Mg, Sr, Mn or Zn.
  • the replacing amount exceeds 50%, a phase having the crystalline structure according to the present invention may be unobtainable.
  • the most preferred replacing amount of Ca is up to 10%.
  • the phosphor of the present invention up to 50% of La may be replaced with Y, Lu, Sc, Gd, Tb or Ce.
  • the replacing amount exceeds 50%, a phase having the crystalline structure according to the present invention may be unobtainable.
  • the most preferred replacing amount of La is up to 10%.
  • the dissolved amount of the activator when the dissolved amount of the activator is less than 0.001a, the amount of the light emitting element is insufficient, and the luminance may be insufficient. When the dissolved amount exceeds 0.4a, the luminance may be rather decreased due to a concentration quenching effect. Thus, the high luminance may be obtained when the dissolved amount of the activator is 0.001a to 0.4a. More preferably, the dissolved amount of the activator is in the range of 0.03 to 0.07 molar ratio.
  • europium is preferred, and at least one element selected from Mn, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm and Yb may be co-doped into the europium.
  • the phosphor having the composition according to the present invention preferably has a single phase.
  • inevitable amount of amorphous or other crystalline phases other than the monoclinic phase may be included.
  • a portion of a mixture including the amorphous phase or other crystalline phase may be included only when no adverse effect is generated onto the properties of the phosphor.
  • the mean particle size of the phosphor of the present invention is preferably 1 to 20 ⁇ m.
  • the mean particle size is less than 1 ⁇ m, a light absorbing ratio due to scattering may be deteriorated, and homogeneous dispersion in a resin sealing an LED may be difficult.
  • the mean particle size exceeds 20 ⁇ m, the light emitting intensity and the color of the phosphor may become non-uniform.
  • silicon nitride (Si 3 N 4 ), calcium oxide (CaO), lanthanum oxide (LaO) and europium oxide (Eu 2 O 3 ) powders were used as raw materials for manufacturing the phosphor when using Si, Ca, La and Eu as the main components.
  • silicon nitride (Si 3 N 4 ), calcium oxide (CaO), lanthanum oxide (LaO) and europium oxide (Eu 2 O 3 ) powders were used.
  • Ba, Mg, Sr and Mn components for replacing Ca respective oxide powder thereof was used.
  • Y, Lu, Sc, Gd, Tb and Ce components for replacing La respective oxide powder thereof was used as Y, Lu, Sc, Gd, Tb and Ce components for replacing La.
  • Raw materials of CaO, La 2 O 3 and a-Si 3 N 4 were weighed and mixed to prepare in a certain composition. In this case, the amount of the mixture per sample was 1.5 g.
  • the raw material of the activator was added by 0.04 mol with respect to Ca and La.
  • the mixing process of the raw materials was conducted manually for 10 minutes in an atmosphere.
  • a baking process of the thus prepared mixture samples was conducted in a nitrogen gas atmosphere including a nitrogen gas as a main component and 0 to 25% of a H 2 gas under the pressure of from an atmospheric pressure to 20 atm.
  • a nitrogen gas atmosphere including a nitrogen gas as a main component and 0 to 25% of a H 2 gas under the pressure of from an atmospheric pressure to 20 atm.
  • the decomposition of a nitride synthesized during the baking at a high temperature may be prevented or restrained, and the composition deviation of the nitride may be decreased to manufacture a phosphor composition having a good performance.
  • the inclusion of the nitrogen gas as the main component means that 75% or more of the nitrogen gas based on the total gas is included.
  • the baking temperature is preferably in the range of 1,300° C. to 1,800° C., and is more preferably 1,500° C. or over to obtain a phosphor having a high quality.
  • the baking time may be in a range of 30 minutes to 100 hours. When considering the quality
  • the baking was conducted in a high purity nitrogen gas atmosphere (99.999%) under an atmospheric pressure at 1,500° C. for 2 hours, and a pulverizing process was conducted to manufacture the phosphor.
  • Examples 1 to 7 are conducted to confirm the difference of light emitting properties according to the molar ratio of the activator Eu 2+
  • the following Examples 8 to 10 are conducted to confirm the difference of light emitting properties when a portion of Ca is replaced with Mg, Sr and Ba
  • the following Examples 11 to 14 are conducted to confirm the difference of light emitting properties when a portion of La is replaced with Y, Lu, Sc, Gd and Tb
  • the following Examples 15 and 16 are conducted to confirm the difference of light emitting properties when using Ce and Mn as the activator instead of Eu.
  • the raw materials of the phosphor composition of Example 1 After respectively weighing 0.2070 g of CaO, 0.6013 g of La 2 O 3 , 0.6911 g of a-Si 3 N 4 , and 0.0007 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 1, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture.
  • Example 2 After respectively weighing 0.2053 g of CaO, 0.5964 g of La 2 O 3 , 0.6917 g of a-Si 3 N 4 , and 0.0065 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 2, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit green light when using an excitation source of 460 nm.
  • Example 3 After respectively weighing 0.2022 g of CaO, 0.5874 g of La 2 O 3 , 0.6930 g of a-Si 3 N 4 , and 0.0174 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 3, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit greenish yellow light when using an excitation source of 460 nm.
  • Example 4 After respectively weighing 0.1997 g of CaO, 0.5802 g of La 2 O 3 , 0.6939 g of a-Si 3 N 4 , and 0.0261 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 4, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 5 After respectively weighing 0.1979 g of CaO, 0.5748 g of La 2 O 3 , 0.6947 g of a-Si 3 N 4 , and 0.0327 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 5, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 6 After respectively weighing 0.1960 g of CaO, 0.5693 g of La 2 O 3 , 0.6954 g of a-Si 3 N 4 , and 0.0393 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 6, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 7 After respectively weighing 0.1922 g of CaO, 0.5584 g of La 2 O 3 , 0.6969 g of a-Si 3 N 4 , and 0.0524 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 7, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 8 After respectively weighing 0.1796 g of CaO, 0.5825 g of La 2 O 3 , 0.6967 g of a-Si 3 N 4 , 0.0150 g of MgO and 0.0262 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 8, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 9 After respectively weighing 0.1768 g of CaO, 0.5735 g of La 2 O 3 , 0.6859 g of a-Si 3 N 4 , 0.0380 g of SrO, and 0.0258 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 9, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 10 After respectively weighing 0.1747 g of CaO, 0.5666 g of La 2 O 3 , 0.6776 g of a-Si 3 N 4 , 0.0556 g of BaO, and 0.0255 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 10, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 11 After respectively weighing 0.1764 g of CaO, 0.5722 g of La 2 O 3 , 0.6843 g of a-Si 3 N 4 , 0.0413 g of Y 2 O 3 , and 0.0258 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 11, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 12 After respectively weighing 0.1754 g of CaO, 0.5687 g of La 2 O 3 , 0.6802 g of a-Si 3 N 4 , 0.0501 g of Sc 2 O 3 , and 0.0256 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 12, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit greenish yellow light when using an excitation source of 460 nm.
  • Example 13 After respectively weighing 0.1736 g of CaO, 0.5628 g of La 2 O 3 , 0.6731 g of a-Si 3 N 4 , 0.0652 g of Gd 2 O 3 , and 0.0253 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 13, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 14 After respectively weighing 0.1733 g of CaO, 0.5620 g of La 2 O 3 , 0.6722 g of a-Si 3 N 4 , 0.0672 g of Tb 4 O 7 , and 0.0253 g of Eu 2 O 3 , as the raw materials of the phosphor composition of Example 14, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit yellow light when using an excitation source of 460 nm.
  • Example 15 After respectively weighing 0.1897 g of CaO, 0.5906 g of La 2 O 3 , 0.6781 g of a-Si 3 N 4 , and 0.0416 g of CeO 2 , as the raw materials of the phosphor composition of Example 15, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit blue light when using an excitation source of 400 nm.
  • Example 16 After respectively weighing 0.1982 g of CaO, 0.5757 g of La 2 O 3 , 0.7082 g of a-Si 3 N 4 , and 0.0179 g of MnO, as the raw materials of the phosphor composition of Example 16, the raw materials were manually mixed by using a mortar and pestle in an air atmosphere to obtain 1.5 g of a raw material powder mixture. Then, the same procedure as described in Example 1 was conducted to obtain a phosphor composition. The thus obtained phosphor was confirmed to emit blue light when using an excitation source of 400 nm.
  • the crystalline structures of the phosphor compositions according to Examples 4, and 8 to 14 of the present invention were analyzed through an XRD and TEM. After conducting the XRD analysis, a precise X-ray diffraction analysis was conducted by using a synchrotron radiation X-ray diffraction (SR-XRD) with respect to the phosphor manufactured according to Example 4.
  • SR-XRD synchrotron radiation X-ray diffraction
  • FIG. 1A is a diagram illustrating a synchrotron radiation X-ray diffraction (SR-XRD) analysis result of a phosphor manufactured according to Example 4 of the present invention
  • FIG. 1B is an analysis result of a phosphor manufactured according to Example 4 of the present invention by using a common XRD analysis apparatus
  • FIG. 2 is a diagram illustrating an XRD analysis result on the phosphors manufactured according to Examples 8 to 14 of the present invention when Ca or La is replaced with Mg, Sr, Ba, Y, Sc, Gd or Tb in a host material by about 10%, along with that according to Example 4.
  • representative diffraction peaks are illustrated in the ranges of Bragg angles (2 ⁇ ) of 10.68° to 11.41°, 18.52° to 19.46°, 31.58° to 31.21° and 36.81° to 37.49° (the ranges sectioned by vertical lines in FIGS. 1A and 1B ) for the phosphor manufactured according to Example 4 of the present invention.
  • the representative diffraction peaks have relative intensity of greater than or equal to 5% when the relative intensity of the most intensive diffraction peak in a powder X-ray diffraction pattern is 100%.
  • the phosphors according to Examples 8 to 14 of the present invention obtained by replacing Ca or La with Mg, Sr, Ba, Y, Sc, Gd, or Tb, have substantially the same crystalline structure as that of the phosphor according to Example 4 and illustrate little change.
  • the amount of the replacing component is increased and exceeds 50%, the composition having the monoclinic crystalline structure according to the present invention may be unobtainable.
  • the replacing amount of the above-described elements is preferably less than or equal to 10%.
  • the host material of the phosphor was confirmed to have a monoclinic crystalline structure.
  • the analysis results of the crystalline structure by using TEM SAED in FIG. 5 also support the above analyzed result.
  • the phosphor having the above described crystalline structure is novel and unknown until now.
  • Example 4 corresponds to the synchrotron powder XRD analysis result, and the remaining results correspond to XRD analysis results conducted in a laboratory.
  • the inner triangle in FIG. 4 represents the composition range among the amounts of Ca, La and Si for obtaining a single phase having a monoclinic crystalline structure according to the present invention through experiments by the present inventors.
  • the composition range deviates from the given composition range, the single phase having the crystalline structure as the phosphor according to the examples of the present invention may be unobtainable.
  • FIGS. 5 and 6 are diagrams illustrating the difference in light emitting properties of the phosphors according to Examples 1 to 7 of the present invention including different Eu 2+ doping amount in the same host material.
  • FIG. 5 illustrates the relative intensity of the luminescence and
  • FIG. 6 illustrates the normalized result of the intensity.
  • the luminance is very low when the Eu 2+ doping amount is 0.001 in a molar ratio, is good when Eu 2 ⁇ doping amounts are 0.04, 0.05 and 0.06, and is the best when Eu 2+ doping amount is 0.04.
  • the most preferable Eu 2+ doping amount are 0.03 to 0.07.
  • the light emitting peak gradually shifts to a longer wavelength region according to the Eu 2+ doping amount, and various light emitting colors from greenish yellow to dark yellow may be obtained according to the change of the Eu 2+ doping amount.
  • FIG. 7 is a diagram illustrating light emitting properties of the phosphors manufactured according to Examples 8 to 14 of the present invention and illustrates normalized results. As confirmed in FIG. 7 , the peak wavelength was 550 to 560 nm and illustrated yellow color when the same Eu 2+ was used as the activator. The peak wavelength difference according to the replacing materials was not found.
  • FIG. 8 is a diagram illustrating the light emitting properties of the phosphors manufactured according to Examples 15 and 16 of the present invention and illustrates normalized results. As confirmed in FIG. 8 , the peak wavelength was illustrated at near about 500 nm when exposed to an excitation source of 400 nm and illustrated blue color when Ce or Mn was used as the activator.
  • the phosphor composition of the present invention is found to emit wide range of light from blue to yellow according to the kind of the activator or the control of the amount of the activator.
  • the phosphor may be appropriately used as yellow phosphor.

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